The Cell Bank/Immunology Core will provide services and reagents to support the work of DERC investigators in several different research areas. The Core will provide both rodent and human islets to investigators who use them for experimental purposes. The Core will isolated islets from transgenic animals. many of which may express transgenes in the islet cells. These islets will be characterized metabolically by Stimulation Index, and in the future, by perifusion studies. Analysis of islet cells as well as purified populations will also be provided by fluorescence activated cell sorting. Through interactions with the Islet Cell Resource Center, the Core will provide human islets for investigators. We anticipate that this will be an important reagent in bringing new discoveries from the laboratory to clinical applications. The Core will acquire and maintain a Flow Cytometer for analysis use and provide support for cell sorting through interactions with the Flow Cytometry Core in the Irving Cancer Center. Finally, to give investigators reagents to directly study human disease pathogenesis including genetic studies to identify genes involved in the cause of the disease and complications, the Core will maintain and characterize a cell bank of peripheral blood mononuclear cells from patients. These will include patients with Type 1 and Type 2 diabetes as well as individuals at high risk for development of diabetes. B lymphocyte cell lines will be prepared and used in genetic studies as well as functional assays.